DRO questions

Suzuki4evr

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I can't afford expensive DRO'S......so are these ok and wich scales are preferable, the normal size or slimline?
javascript:void(0)s-l400.jpg
 

pontiac428

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Normal vs. slim is first a matter of glass vs. magnetic. Glass scales (like those pictured) are great at what they do, and offer good resolution for the price. The down side is that they can get dirty from all of the flying chips, oil, and coolant at your machine. Slim scales are now available in resolutions comparable to glass scales, but in a smaller, easier to mount package that is more resistant to chips and crud. Some installs do not allow much room to fit scales, so the extra space afforded by magnetic scales is a boon. Without a big cost or performance difference, today it makes the most sense to go with slim magnetic scales. The head units offer varying functionality and their capabilities are self-explanatory. There are a few common layouts based on whoever originally produced that style of head, i.e. Sony vs. Mitsutoyo. I prefer the Sony style (as a TI user) but people who like HP RPN calculators like Mitsutoyo better (get it?). It's preference at that point, because all heads will give you abs/incr, tool offsets, and bolt patterns, etc. so shop around for what you like. For a knee mill, it's nice to know what your Z axis options are, for instance.
 

SamI

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I'd agree with the magnetic scales - I had glass opticals on my lathe but replaced them as after a year or so they started getting a little unreliable. Sure, cleaning them with alcohol bought them some new life but I found myself not trusting them as I got caught out a few times costing me a lot of wasted time and material.

Not sure if there's much difference in the displays although when looking for a DRO system for my Bridgeport I did notice some didn't have a huge SDM memory. If you're not familiar with DRO's it stands for Sub Datum Memory - basically you can programme a number of coordinates then when it comes to machining you just travel to 0.000 on the display and make your cut. I use it a lot on the lathe for batch runs of parts. You make the first part and "programme" your DRO as you go then just smash out the rest without having to pay attention to dimensions. On the mill it can be handy for plugging in the coordinates for holes and other features. You'll probably never need as many as 200 but some only offer 20 or so and I think that would limit you a little so in my opinion it's worth going for one with 200 SDM memory, assuming there is negligible cost difference.
 

RJSakowski

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Glass scales come in both standard and slim line versions but the difference between the two isn't that great. Magnetic scales are considerable smaller than either of the glass scale sizes.
 

RJSakowski

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I have had a three axis glass scale DRO on my mill for fifteen years and have yet to have it malfunction. IMO, the secret is providing a suitable scale guard. The x and y scale guards are mounted so that any oil, coolant, or chips would have to reverse direction to reach the scale seals. The z axis is more vulnerable but still no problems.
 

Suzuki4evr

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I am just asking. How much does one use the z-axis scale? I am contemplating if I must get a 3-axis or 2-axis DRO.
 

darkzero

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With budget in mind go with glass scales if you don't have mounting constraint issues. Glass slimline cost a bit more than standard & then of course magnetic costs the most. Good thing about mag scales is you can cut them if you need a size not offered in glass.

I too have not had any issues with my glass scales. The Z scale on my lathe is constantly getting covered with oil from the ways but it's the cover over the scale that is getting covered with oil. I don't run flood coolant but I do spray on coolant with a spray bottle.

The only slim scale I have is for my cross slide on the lathe. Everything else are just the normal size. Not that it may matter much but the scales on my lathe are Sino, 10 yrs no issues. Scales on my mill are Easson, 8 yrs no issues & all still very accurate. If you aren't familiar with those brands, yes they are China.

I do have a Z axis scale on my mill but it rarely gets used. If you can, get a 3 axis mount the 3rd/Z axis to the quill, still Z. I Never bothered to cause I put a DRO scale on my quill before I got the 3 axis DRO.
 

pontiac428

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With BP style mills, some folks run X,Y on the head unit and a smaller battery-powered unit for the quill. This is part because it's not a big deal, but mostly (IMHO) has to do with how bulky a scale mount can be on the BP quill. I reckon this is the most popular setup for home shops.

I just bought a Ditron 4-axis setup with DC10 scales, but haven't installed it yet. That's X,Y, knee and quill. I can sum the knee and quill for a unified Z axis.
 

DAT510

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What type of mill will the DRO be going on?

For my mill, it has a separate (factory) Digital Scale on the Quill. In most cases it's all I need. But the occasions when I've needed to raise or lower the head because quill travel was too short, I was glad I had a Z axis on my DRO. Also on my Medium sized bench mill, I find keeping the quill choked up gives me better accuracy when taking deeper cuts, so in those cases I again use the Z axis DRO and lower head over extending the quill.
 

randyjaco

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If you can afford the Z-axis scale, Get it! You can cheat a little by adapting a cheap digital caliper on the spindle, but being able to accurately control the table height is very convenient.

Randy
 

RJSakowski

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I am just asking. How much does one use the z-axis scale? I am contemplating if I must get a 3-axis or 2-axis DRO.
I rely on my z axis DRO for my round column mill. There is enough backlash in the old beast to create uncertainty and with the fine feed dial at .085"/rev., counting turns and doing the math to calculate travel is too much, not to mention calculation errors. The DRO eliminates all that.
 

Winegrower

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On a Bridgeport, the Z-Axis dial is large, easy to read, and stable. I have not found a need for DRO there. I added a quill DRO, but I use it rarely...mainly when drilling to a critical depth or countersinking.
 

RJSakowski

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One advantage of a z axis DRO is the ability to zero tool offsets off the part the subdatum positions. Below is an example of manual machining using an RT for a 4th axis and the DRO for positioning. It involved 20 tool changes and would have been virtually impossible without the DRO.

StepOperationFaceToolRotary TableDRO DisplayCoordinates, inches
degreesFunctionXYZ
Notes: The following operations are executed on the rotary table in vertical position with the central axis aligned with the mill X axis. The rotary table should be adjusted so that it is square to the mill table to within 0.0005" over 5" travel, using shims if necessary. The 4" 3-jaw chuck is used as the workpiece clamping device. The flexible electrical contact datum point is assigned ABSolute 0,0,0 coordinates and located so that the X and Z coordinates will coincide with those of the workpiece (~8.65" above mill table and 4.75" from rotary table bed). The mill head should be set so there is 1.75 inches of clearance between the top of the head and the column retainer. Operating speed should be set at 1325 rpm. All tools excluding the 1/2" and 7/32" end mills and taps should be chucked in the Tru Center chuck adjusted for < 0.0002" runout.
1​
cut blankbandsawNANA
2​
weld blank to stubsoldering ironNANA
3​
level piecerotary table90/270NA
4​
face side of piece1/2" end millNANAAs Req.VariableN/A
5​
set DROABS0.4600N/AN/A
6​
1st face top1/2" end mill180ABS0.0000VariableAs Req.
7​
set DROINC0.0000N/A0.0000
8​
1st face bottom1/2" end mill0INC0.0000Variable0.0000
9​
measure top-bottom (XXXX)micrometer
10​
set DRO to -1/2 (XXXX)INC0.0000N/A-.5(XXXX)
11​
find top face, set DRO Y1/2" edge finder90INC0.00000.0000As Req.
12​
find bottom face, set center find on DRO Y axis1/2" edge finder90INC0.0000.5(YYYY)As Req.
13​
set absolute coordinates at Z axis datumsharpened scribeABS0.00000.00000.0000
14​
find top face, set DRO Zsharpened scribe, 50X microscope180INC0.19000.0000-.5(XXXX)
15​
find bottom face, check DRO Zsharpened scribe, 50X microscope0INC0.19000.0000-.5(XXXX)
16​
set DRO X,Y,ZSDM 1990.00000.0000-.5(XXXX)
17​
set backup SDM coordinatesSDM 1980.00000.0000-.5(XXXX)
18​
set 2nd backup SDM coordinatesSDM 1000.00000.0000-.5(XXXX)
19​
zero tool Z axis1/2" end millABS0.00000.00000.0000
20​
final face top1/2" end mill180SDM 1990.0000Variable-0.4500
21​
final face bottom1/2" end mill0SDM 1990.0000Variable-0.4500
22​
face SMA1/2" end mill270SDM 1990.0000Variable-0.4490
23​
faceinsert1/2" end mill90SDM 1990.0000Variable-0.1928
24​
zero tool Z axis0000 center drillABS0.00000.00000.0000
25​
drill insert pilot insert0000 center drill90SDM 1990.00000.0000-0.0500
26​
drill bypass pilot bottom0000 center drill0SDM 1990.00000.0000-0.1600
27​
zero tool Z axis0.1875 center drillABS0.00000.00000.0000
28​
drill sample port pilot top0.1875 center drill180SDM 1990.00000.0000-0.1800
29​
drill SMA coupler pilot SMA0.1875 center drill270SDM 1990.00000.0000-0.0500
30​
zero tool Z axis3.35mm carbide drillABS0.00000.00000.0000
31​
drill bypass capillary bushing holebottom3.35mm carbide drill0SDM 1990.00000.0000-0.2373
32​
zero tool Z axis1.55mm drillABS0.00000.00000.0000
33​
drill bypass capillary hole bottom1.55mm drill0SDM 1990.00000.0000-0.0550
34​
zero tool Z axis0.042" carbide pc drillABS0.00000.00000.0000
35​
drill clearance hole for 0.008" drill bottom0.042" carbide pc drill0SDM 1990.00000.0000-0.0250
36​
zero tool Z axis0.020" carbide pc drillABS0.00000.00000.0000
37​
drill large bypass passage bottom0.020" carbide pc drill0SDM 1990.00000.0000-0.0100
38​
zero tool Z axis0.039" carbide pc drillABS0.00000.00000.0000
39​
drill secondary pilottop0.039" carbide pc drill180SDM 1990.00000.0000-0.0500
40​
zero tool Z axis7o taper toolABS0.00000.00000.0000
41​
bore lower sample port top7o taper tool180SDM 1990.00000.0000-0.0600
42​
zero tool Z axisdual taper cone toolABS0.00000.00000.0000
43​
bore upper sample port topdual taper cone tool180SDM 1990.00000.0000-0.0500
44​
zero tool Z axis0.008 micro drillABS0.00000.00000.0000
45​
drill final passagetop0.008 micro drill180SDM 1990.00000.00000.0030
46​
drill final passagebottom0.008 micro drill0SDM 1990.00000.00000.0030
47​
zero tool Z axis120o c/sinkABS0.00000.00000.0000
48​
cut 120o bevelSMA120o c/sink270SDM 1990.00000.0000-0.0090
49​
cut 120o bevelinsert120o c/sink90SDM 1990.00000.0000-0.0090
50​
zero tool Z axis0.008 micro drillABS0.00000.00000.0000
51​
drill optical passageSMA0.008 micro drill270SDM 1990.00000.00000.0160
52​
zero tool Z axis0000 center drillABS0.00000.00000.0000
53​
drill locating pin #1 pilotinsert0000 center drill90SDM 1990.12000.3100-0.1256
54​
drill locating pin #2 pilotinsert0000 center drill90SDM 199-0.1200-0.3100-0.1256
55​
drill #2-56 fastener #1 pilot insert0000 center drill90SDM 199-0.1000-0.1950-0.1070
56​
drill #2-56 fastener #2 pilot insert0000 center drill90SDM 199-0.10000.1950-0.1070
57​
drill #2-56 fastener #3 pilot insert0000 center drill90SDM 1990.10000.1950-0.1070
58​
drill #2-56 fastener #4 pilot insert0000 center drill90SDM 1990.1000-0.1950-0.1070
59​
zero tool Z axis#51 drillABS0.00000.00000.0000
60​
drill #2-56 fastener #1 hole insert#51 drill90SDM 199-0.1000-0.19500.1820
61​
drill #2-56 fastener #2 hole insert#51 drill90SDM 199-0.10000.19500.1820
62​
drill #2-56 fastener #3 hole insert#51 drill90SDM 1990.10000.19500.1820
63​
drill #2-56 fastener #4 hole insert#51 drill90SDM 1990.1000-0.19500.1820
64​
zero tool Z axis1.55mm drillABS0.00000.00000.0000
65​
drill locating pin hole #1insert1.55mm drill90SDM 1990.12000.31000.0572
66​
drill locating pin hole #2insert1.55mm drill90SDM 199-0.1200-0.31000.0572
67​
zero tool Z axis7/32 end millABS0.00000.00000.0000
68​
c/bore SMA connector holeSMA7/32 end mill270SDM 1990.00000.0000-0.1690
69​
tap #2-56 hole #1insert#2-56 tap90SDM 199-0.1000-0.1950N/A
70​
tap #2-56 hole #2insert#2-56 tap90SDM 199-0.10000.1950N/A
71​
tap #2-56 hole #3insert#2-56 tap90SDM 1990.10000.1950N/A
72​
tap #2-56 hole #4insert#2-56 tap90SDM 1990.1000-0.1950N/A
73​
tap SMA connector holeSMA1/4-36 plug tap 270SDM 1990.00000.0000N/A
74​
tap SMA connector holeSMA1/4-36 bottoming tap270SDM 1990.00000.0000N/A
75​
zero tool Z axis1/2" end millABS0.00000.00000.0000
76​
cut weldSMA1/2" end mill270SDM 199As Req.Variable-0.4700
77​
cut weldbottom1/2" end mill0SDM 199As Req.Variable-0.4700
78​
cut weldinsert1/2" end mill90SDM 199As Req.Variable-0.1950
79​
cut weldtop1/2" end mill180SDM 199As Req.Variable-0.4700
Notes: the final operations are performed on the mill table using a conventional mill vise. The vise should be adjusted so that it is square and parallel to the mill table to within 0.0005" over 3" travel, using shims if necessary. The flexible electrical contact datum point is assigned ABSolute 0,0,0 coordinates and located so that the Y and Z coordinates will aproximately coincide with those of the workpiece. A buildup block should be used to bring the bottom workpiece support to 0.32 to 0.33" from the top of the vise jaws. This block can be milled in place to ensure parallel conditions for the workpiece.
StepOperationFaceToolRotary TableDRO DisplayCoordinates, inches
degreesFunctionXYZ
1​
find top face, set DRO Y1/2" edge finderINC0.00000.0000As Req.
2​
set absolute coordinates at X, Y axis datum1/2" edge finderABS0.00000.00000.0000
3​
set absolute coordinates at Z axis datum2mm pinABS0.00000.00000.0000
4​
find buildup block floor, set DRO Z2mm pin, feeler gaugeSDM 001NANA0.0000
5​
find buildup block far surface, set DRO YSDM 001NA0.0000As Req.
6​
zero tool Z axis1/2" end millABS0.20000.00000.0000
7​
clamp workpiece in vise, milled side down
8​
first face back1/2" end millSDM 199As Req.Variable-0.5800
9​
second faceback1/2" end millSDM 199As Req.Variable-0.5200
10​
third faceback1/2" end millSDM 199As Req.Variable-0.4600
11​
fourth faceback1/2" end millSDM 199As Req.Variable-0.4000
12​
fifth faceback1/2" end millSDM 199As Req.Variable-0.3600
13​
final faceback1/2" end millSDM 199As Req.Variable-0.3571
14​
reverse workpiece in vise with sample port to fixed jaw
15​
final facefront1/2" end millSDM 199As Req.Variable-0.3543
16​
drill mounting hole #1 throughfront120o c/sinkSDM 1990.19900.1500through
17​
drill mounting hole #2 throughfront120o c/sinkSDM 1990.19900.7500through
 

MrWhoopee

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I got this one for my lathe

1571802883373.png

It's decently made and has been trouble free, quite satisfied.

I see the one you're looking at is even cheaper, that's a spectacular price.
I like the colors too.

On a mill, the scale width is not a real big issue. You might lose a little travel, but not enough to worry about (unless it's a mini).

I put an ARO (analog readout) on the quill of my mill. Only 1 in. range, but infinitely adjustable.
WP_20191022_21_25_18_Pro[1].jpg
 
Last edited:

MrWhoopee

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Suzuki4evr

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What type of mill will the DRO be going on?

For my mill, it has a separate (factory) Digital Scale on the Quill. In most cases it's all I need. But the occasions when I've needed to raise or lower the head because quill travel was too short, I was glad I had a Z axis on my DRO. Also on my Medium sized bench mill, I find keeping the quill choked up gives me better accuracy when taking deeper cuts, so in those cases I again use the Z axis DRO and lower head over extending the quill.
It is a knee mill
20180518_091652.jpg
 

Suzuki4evr

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Suzuki4evr

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I got this one for my lathe

View attachment 304465

It's decently made and has been trouble free, quite satisfied.

I see the one you're looking at is even cheaper, that's a spectacular price.
I like the colors too.

On a mill, the scale width is not a real big issue. You might lose a little travel, but not enough to worry about (unless it's a mini).

I put an ARO (analog readout) on the quill of my mill. Only 1 in. range, but infinitely adjustable.
View attachment 304466
Your DRO looks nice,but shipping to SA is very expensive, almost half the price of the DRO.
 

Suzuki4evr

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I have had a three axis glass scale DRO on my mill for fifteen years and have yet to have it malfunction. IMO, the secret is providing a suitable scale guard. The x and y scale guards are mounted so that any oil, coolant, or chips would have to reverse direction to reach the scale seals. The z axis is more vulnerable but still no problems.
Do you have some pics of your setup?
 

RJSakowski

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Do you have some pics of your setup?
I can take some.
I also did a 3 axis DRO using Easson scales for a Grizzly G0755 mill. I have a complete set of SolidWorks build files for that. There is a thread for my G0602 lathe DRO using iGaging scales and Yuriy's Touch DRO on the HM site.
 

Suzuki4evr

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I got this one for my lathe

View attachment 304465

It's decently made and has been trouble free, quite satisfied.

I see the one you're looking at is even cheaper, that's a spectacular price.
I like the colors too.

On a mill, the scale width is not a real big issue. You might lose a little travel, but not enough to worry about (unless it's a mini).

I put an ARO (analog readout) on the quill of my mill. Only 1 in. range, but infinitely adjustable.
View attachment 304466
For how long have you had this model and how would you rate the quality?
 

MrWhoopee

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For how long have you had this model and how would you rate the quality?
I've had it for a little more than a year. It hasn't seen a lot of use, but it's been exposed to sub-freezing temps and multiple power outages and blinks. I would rate the quality as surprisingly good. The electronics work well and the construction is solid. Nothing feels cheap or flimsy.
 

Gravydog

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I can't afford expensive DRO'S......so are these ok and wich scales are preferable, the normal size or slimline?
Hi, not trying to blow my own horn (not much!) but you and others reading this thread might be interested in my post in another forum on the DRO I chose:


Hope it helps your search.

Rob
 
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